Adaptive extrapolation filter-based intra prediction

Abstract

Aspects of the disclosure includes methods and apparatuses for video decoding and video encoding and a method of processing visual media data. The apparatus for video decoding includes processing circuitry configured to: receive coded information indicating that a current block in a current picture is predicted according to an extrapolation filter-based intra prediction (EIP) mode; determine at least one of (i) one or more available template types from a set of template types and (ii) one or more available filter types from a set of filter types used in the EIP mode based on size information of the current block and at least one threshold value; determine a predicted value of a current sample in the current block according to the EIP mode with the at least one of (i) the one or more available template types and (ii) the one or more available filter types.

What is claimed is: 
     
         1 . An apparatus for video decoding, comprising:
 processing circuitry configured to:
 receive coded information indicating that a current block in a current picture is predicted according to an extrapolation filter-based intra prediction (EIP) mode; 
 determine at least one of (i) one or more available template types from a set of template types and (ii) one or more available filter types from a set of filter types used in the EIP mode based on size information of the current block and at least one threshold value; 
 determine a predicted value of a current sample in the current block according to the EIP mode with the at least one of (i) the one or more available template types and (ii) the one or more available filter types; and 
 reconstruct the current sample based on the predicted value of the current sample. 
   
     
     
         2 . The apparatus of  claim 1 , wherein
 the at least one of (i) the one or more available template types and (ii) the one or more available filter types includes the one or more available template types and the one or more available filter types of the EIP mode;   the size information includes first size information and second size information;   the at least one threshold value includes a first threshold value and a second threshold value; and   the processing circuitry is configured to:   determine the one or more available template types based on the first size information of the current block and the first threshold value; and   determine the one or more available filter types based on the second size information of the current block and the second threshold value.   
     
     
         3 . The apparatus of  claim 1 , wherein the at least one threshold value is predefined or signaled in a high level syntax associated with a level that is higher than the current block. 
     
     
         4 . The apparatus of  claim 1 , wherein
 the size information comprises one of (i) a width w of the current block; (ii) a height h of the current block; (iii) an area w×h of the current block; (iv) a ratio between the width w and the height h indicating w/h of the current block; and   the set of template types includes a first template type TPL 0  consisting of neighboring reconstructed samples above the current block and to the left of the current block, a second template type TPL 1  consisting of neighboring reconstructed samples above the current block, and a third template type TPL 2  consisting of neighboring reconstructed samples to the left of the current block.   
     
     
         5 . The apparatus of  claim 4 , wherein
 the size information comprises the width w of the current block;   the at least one threshold value includes a threshold value; and   the processing circuitry is configured to determine the one or more available template types based on one of:   (i) the one or more available template types consists of {TPL 1 } when w is greater than or equal to the threshold value;   (ii) the one or more available template types consists of {TPL 0 } when w is greater than or equal to the threshold value;   (iii) the one or more available template types consists of {TPL 0 , TPL 1 } when w is greater than or equal to the threshold value;   (iv) the one or more available template types consists of {TPL 0 } when w is less than or equal to the threshold value; and   (v) the one or more available template types consists of {TPL 0 , TPL 2 } when w is less than or equal to the threshold value.   
     
     
         6 . The apparatus of  claim 4 , wherein
 the size information comprises the height h of the current block;   the at least one threshold value includes a threshold value; and   the processing circuitry is configured to determine the one or more available template types based on one of:   (i) the one or more available template types consists of {TPL 2 }, when h is greater than or equal to the threshold value;   (ii) the one or more available template types consists of {TPL 0 } when h is greater than or equal to the threshold value;   (iii) the one or more available template types consists of {TPL 0 , TPL 2 } when h is greater than or equal to the threshold value;   (iv) the one or more available template types consists of {TPL 0 } when h is less than or equal to the threshold value; and   (v) the one or more available template types consists of {TPL 0 , TPL 1 } when h is less than or equal to the threshold value.   
     
     
         7 . The apparatus of  claim 4 , wherein
 the size information comprises the area w×h of the current block;   the at least one threshold value includes a threshold value; and   the processing circuitry is configured to determine the one or more available template types based on one of:   (i) the one or more available template types consists of {TPL 0 } when w×h is greater than or equal to the threshold value; and   (ii) the one or more available template types consists of {TPL 0 } when w×h is less than or equal to the threshold value.   
     
     
         8 . The apparatus of  claim 1 , wherein
 the size information comprises one of (i) a width w of the current block; (ii) a height h of the current block; (iii) an area w×h of the current block; (iv) a ratio between the width w and the height h indicating w/h; and   the set of filter types includes a first filter type F 0  with a number of input samples in a vertical direction that is equal to a number of the input samples in a horizontal direction, a second filter type F 1  with a number of input samples in the horizontal direction that is greater than a number of the input samples in the vertical direction, and a third filter type F 2  with a number of input samples in the vertical direction that is greater than a number of the input samples in the horizontal direction.   
     
     
         9 . The apparatus of  claim 1 , wherein the processing circuitry is configured to:
 when the at least one of (i) the one or more available template types and (ii) the one or more available filter types consists of the one or more available template types,
 determine, using second size information of the current block and at least one second threshold value, context modeling used in context coding of a filter type selected for the current block; 
 decode the filter type from the coded information based on the determined context modeling; and 
 determine the predicted value of the current sample using the EIP mode with the one or more available template types and the decoded filter type; and 
   when the at least one of (i) the one or more available template types and (ii) the one or more available filter types consists of the one or more available filter types,
 determine, using second size information of the current block and at least one second threshold value, context modeling used in context coding of a template type selected for the current block; 
 decode the template type from the coded information based on the determined context modeling; and 
 determine the predicted value of the current sample using the EIP mode with the decoded template type and the one or more available filter types. 
   
     
     
         10 . The apparatus of  claim 9 , wherein
 the second size information used to determine the context modeling comprises one of (i) a width w of the current block; (ii) a height h of the current block; (iii) an area w×h of the current block; (iv) a ratio between the width w and the height h indicating w/h; and   the context modeling is one of a first context set and a second context set.   
     
     
         11 . A method for video encoding, the method comprising:
 determining at least one of (i) one or more available template types from a set of template types and (ii) one or more available filter types from a set of filter types used in an extrapolation filter-based intra prediction (EIP) mode based on size information of a current block in a current picture that is predicted according to the EIP mode and at least one threshold value;   determining a predicted value of a current sample in the current block according to the EIP mode with the at least one of (i) the one or more available template types and (ii) the one or more available filter types; and   encoding the current sample based on the predicted value of the current sample.   
     
     
         12 . The method of  claim 11 , wherein
 the at least one of (i) the one or more available template types and (ii) the one or more available filter types includes the one or more available template types and the one or more available filter types of the EIP mode;   the size information includes first size information and second size information;   the at least one threshold value includes a first threshold value and a second threshold value; and   the determining the at least one of (i) the one or more available template types and (ii) the one or more available filter types includes:
 determining the one or more available template types based on the first size information of the current block and the first threshold value; and 
 determining the one or more available filter types based on the second size information of the current block and the second threshold value. 
   
     
     
         13 . The method of  claim 11 , wherein the at least one threshold value is predefined or signaled in a high level syntax associated with a level that is higher than the current block. 
     
     
         14 . The method of  claim 11 , wherein
 the size information comprises one of (i) a width w of the current block; (ii) a height h of the current block; (iii) an area w×h of the current block; (iv) a ratio between the width w and the height h indicating w/h of the current block; and   the set of template types includes a first template type TPL 0  consisting of neighboring reconstructed samples above the current block and to the left of the current block, a second template type TPL 1  consisting of neighboring reconstructed samples above the current block, and a third template type TPL 2  consisting of neighboring reconstructed samples to the left of the current block.   
     
     
         15 . The method of  claim 14 , wherein
 the size information comprises the width w of the current block;   the at least one threshold value includes a threshold value; and   the determining the one or more available template types includes determining the one or more available template types based on one of:   (i) the one or more available template types consists of {TPL 1 } when w is greater than or equal to the threshold value;   (ii) the one or more available template types consists of {TPL 0 } when w is greater than or equal to the threshold value;   (iii) the one or more available template types consists of {TPL 0 , TPL 1 } when w is greater than or equal to the threshold value;   (iv) the one or more available template types consists of {TPL 0 } when w is less than or equal to the threshold value; and   (v) the one or more available template types consists of {TPL 0 , TPL 2 } when w is less than or equal to the threshold value.   
     
     
         16 . The method of  claim 14 , wherein
 the size information comprises the height h of the current block;   the at least one threshold value includes a threshold value; and   the determining the one or more available template types includes determining the one or more available template types based on one of:   (i) the one or more available template types consists of {TPL 2 }, when h is greater than or equal to the threshold value;   (ii) the one or more available template types consists of {TPL 0 } when h is greater than or equal to the threshold value;   (iii) the one or more available template types consists of {TPL 0 , TPL 2 } when h is greater than or equal to the threshold value;   (iv) the one or more available template types consists of {TPL 0 } when h is less than or equal to the threshold value; and   (v) the one or more available template types consists of {TPL 0 , TPL 1 } when h is less than or equal to the threshold value.   
     
     
         17 . The method of  claim 14 , wherein
 the size information comprises the area w×h of the current block;   the at least one threshold value includes a threshold value; and   the determining the one or more available template types includes determining the one or more available template types based on one of:   (i) the one or more available template types consists of {TPL 0 } when w×h is greater than or equal to the threshold value; and   (ii) the one or more available template types consists of {TPL 0 } when w×h is less than or equal to the threshold value.   
     
     
         18 . The method of  claim 11 , wherein
 the size information comprises one of (i) a width w of the current block; (ii) a height h of the current block; (iii) an area w×h of the current block; (iv) a ratio between the width w and the height h indicating w/h; and   the set of filter types includes a first filter type F 0  with a number of input samples in a vertical direction that is equal to a number of the input samples in a horizontal direction, a second filter type F 1  with a number of input samples in the horizontal direction that is greater than a number of the input samples in the vertical direction, and a third filter type F 2  with a number of input samples in the vertical direction that is greater than a number of the input samples in the horizontal direction.   
     
     
         19 . A non-transitory computer readable medium storing a video media bitstream encoded by an encoding method, the encoding method comprising:
 determining at least one of (i) one or more available template types from a set of template types and (ii) one or more available filter types from a set of filter types used in an extrapolation filter-based intra prediction (EIP) mode based on size information of a current block in a current picture that is predicted according to the EIP mode and at least one threshold value;   determining a predicted value of a current sample in the current block according to the EIP mode with the at least one of (i) the one or more available template types and (ii) the one or more available filter types; and   encoding the current sample based on the predicted value of the current sample.   
     
     
         20 . The method of  claim 19 , wherein
 the at least one of (i) the one or more available template types and (ii) the one or more available filter types includes the one or more available template types and the one or more available filter types of the EIP mode;   the size information includes first size information and second size information;   the at least one threshold value includes a first threshold value and a second threshold value; and   the determining the at least one of (i) the one or more available template types and (ii) the one or more available filter types includes:
 determining the one or more available template types based on the first size information of the current block and the first threshold value; and 
 determining the one or more available filter types based on the second size information of the current block and the second threshold value.